Chemical scavenger for downhole chemical analysis

Abstract

A method for analyzing formation fluid in a subterranean formation is disclosed, wherein the method includes the steps of: adding a scavenger compound to an analytical reagent to form a reagent solution; collecting an amount of formation fluid into a formation tester, wherein the formation tester includes at least one fluids analyzer comprising at least one probe, at least one flow line, at least one reagent container, and at least one spectral analyzer, wherein the fluids analyzer is configured such that the collected formation fluid is fed through the at least one flow line to the at least one spectral analyzer; mixing an amount of the collected formation fluid with an amount of the reagent solution to form a mixture; and analyzing the mixture downhole.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims the priority from U.S. Provisional Application No. 61 / 422,637 filed on Dec. 13, 2010. This application is incorporated by reference in its entirety.BACKGROUND OF INVENTION[0002]1. Field of the Invention[0003]Embodiments disclosed herein relate generally to the analysis and characterization of downhole fluid components.[0004]2. Background Art[0005]Hydrocarbons are found in subterranean formations. Production of such hydrocarbons is generally accomplished through the use of rotary drilling technology, which requires the drilling, completing and working over of wells penetrating producing formations.[0006]During drilling operations, it is desirable to perform various evaluations of the subterranean formations penetrated by the wellbore. In some instances, the drilling tool may be removed from the wellbore and a wireline tool may be deployed into the wellbore to test and / or sample the formation. In other cases, the dri...

AI Technical Summary

Benefits of technology

The patent describes a way to prevent and reduce the damage caused by free radicals on chemicals used in drilling and oil production. The solution is a mixture of a special reagent and another compound called a scavenger. This mixture can protect against the harmful effects of free radicals and make the chemical compounds used in drilling last longer.

Problems solved by technology

However, due to the high pressure and temperature conditions downhole, the organic materials used in the reagents are prone to chemical attacks.

For example, in the case where the reagent includes a polymer based compound, chemical attacks from oxidation and / or free radicals often change the structure and characteristics of the polymer, resulting in changes of color, viscosity, and structure stability of the reagent.

Furthermore, thermal oxidation and free radical attack may cause chain scission of the polymer because its main chain and / or side chain scission rates are accelerated at high temperature.

Additionally, these chemical attacks may result in degradation of the downhole reagent thereby decreasing the quality of the sampled fluid.

Furthermore, such degradation of the downhole reagent may reduce or even prevent the desired changes in fluid properties from occurring and thereby diminish the accuracy of the analytical procedures conducted downhole (e.g., due to loss of coloration of the reagent).

Images